MAYBE

We are left with following problem, upon which TcT provides the
certificate MAYBE.

Strict Trs:
  { f(a, empty()) -> g(a, empty())
  , f(a, cons(x, k)) -> f(cons(x, a), k)
  , g(empty(), d) -> d
  , g(cons(x, k), d) -> g(k, cons(x, d)) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..